Gene Cloning and Expression of an Alkaline Serine Protease with Dehairing Function from Bacillus pumilus

Abstract

A new gene (named AP gene) encoding an alkaline serine protease with dehairing function was cloned from Bacillus pumilus UN-31-C-42 and its nucleotide sequence was determined. The expression of AP gene was induced with IPTG in Escherichia coli after the mature protease region was cloned into pET15b and SDS-PAGE showed expressed product clearly, but no alkaline protease activity was detected. In order to express the AP gene in B. subtilis, a recombinant expression plasmid was constructed which contained a promoter Bp53 (also from B. pumilus), the AP gene and an E. coli–B. subtilis shuttle vector pSUGV4. This plasmid was introduced into B. subtilis WB600 and the transformant displayed the hydrolyzed zone on a milk plate. The expressed product can be easily detected with SDS-PAGE and the fermentation fluid of the transformant showed low alkaline protease activity and dehairing activity. This is the first report of a gene cloned from B. pumilus, encoding an alkaline serine protease, which can alone accomplish the whole dehairing process.